Urinary catheter assemblies for draining the bladder are increasingly used for intermittent as well as indwelling or permanent catheterisation. Typically, urinary catheters are used by patients suffering from urinary incontinence or by disabled individuals like paraplegics or tetraplegics, who may have no control permitting voluntary urination and for whom catheterisation may be the way of urinating.
Urinary catheters are divided into two major groups of catheters, indwelling catheters and intermittent catheters. Indwelling catheters are typically inserted into the urethra and the bladder by medical personal (i.e. a trained professional, typically a nurse or physician) and has means for retaining the catheter inside the bladder for up to two weeks or more. Indwelling catheters are soft and flexible since they have to remain in the urethra for weeks. Indwelling catheters empty the bladder continuously.
Intermittent catheters are typically inserted by the user him- or herself and sits only in the urethra and bladder for as long as it take to empty the bladder—e.g. for about 5-10 minutes. Intermittent catheters are used every 4-6 hours to empty the bladder corresponding roughly to the interval that people having no urinary problems will usually go to the bathroom. Intermittent catheters are typically more rigid than indwelling catheters since they have to be inserted by the user him-/herself and since they do not need to sit in the urethra for days or weeks. An important feature for the intermittent catheter is to ease the insertion into the urethra. This is done by providing the intermittent catheter with a low frictious surface. Non-limiting examples of such are hydrophilic coated catheters which are subsequently wetted by a swelling media in order to produce a low friction surface, or oil or water based gel which is applied to the catheter before insertion into the urethra.
Intermittent urinary catheters may be provided with a hydrophilic coating that needs to be wetted prior to use and thereby absorbs a considerable amount of liquid. Such a hydrophilic coating will provide a very lubricious surface that has very low-friction when the catheter is to be inserted. Hydrophilic coated catheters, where the coating absorbs a considerable amount of liquid for a low frictious surface (swelling degree>100%), will not be suitable for indwelling catheters, because the hydrophilic surface coating would stick inside the mucosa of the urethra if left inside the body for a longer period, due to the hydrophilic coating transforming from being highly lubricious when fully wetted to being adhesive when the hydration level of the coating is reduced.
This invention relates to intermittent catheters with a hydrophilic coating of the kind that is wetted prior to use to absorb a considerable amount of liquid and to provide a very lubricious surface.